fix: insert zero padding after sign and prefix in string/base/format-interpolate

lib/node_modules/@stdlib/string/base/format-interpolate/lib/format_integer.js

@@ -79,15 +79,15 @@ function formatInteger( token ) {
 	if ( i < 0 ) {
 		out = ( -i ).toString( base );
 		if ( token.precision ) {
-			out = zeroPad( out, token.precision, token.padRight );
+			out = zeroPad( out, token.precision, false );
 		}
 		out = '-' + out;
 	} else {
 		out = i.toString( base );
 		if ( !i && !token.precision ) {
 			out = '';
 		} else if ( token.precision ) {
-			out = zeroPad( out, token.precision, token.padRight );
+			out = zeroPad( out, token.precision, false );
 		}
 		if ( token.sign ) {
 			out = token.sign + out;

lib/node_modules/@stdlib/string/base/format-interpolate/lib/zero_pad.js

@@ -18,18 +18,13 @@
 
 'use strict';
 
-// FUNCTIONS //
+// VARIABLES //
 
-/**
-* Tests if a string starts with a minus sign (`-`).
-*
-* @private
-* @param {string} str - input string
-* @returns {boolean} boolean indicating if a string starts with a minus sign (`-`)
-*/
-function startsWithMinus( str ) {
-	return str[ 0 ] === '-';
-}
+// Sign (`-`, `+`, or ` `) and/or hexadecimal prefix (`0x` or `0X`), which must precede any zeros:
+var RE_PREFIX = /^[-+ ]?(?:0[xX])?/;
+
+
+// FUNCTIONS //
 
 /**
 * Returns a string of `n` zeros.
@@ -60,22 +55,17 @@ function zeros( n ) {
 * @returns {string} padded token argument
 */
 function zeroPad( str, width, right ) {
-	var negative = false;
+	var prefix;
 	var pad = width - str.length;
 	if ( pad < 0 ) {
 		return str;
 	}
-	if ( startsWithMinus( str ) ) {
-		negative = true;
-		str = str.substr( 1 );
-	}
+	prefix = RE_PREFIX.exec( str )[ 0 ];
+	str = str.substring( prefix.length );
 	str = ( right ) ?
 		str + zeros( pad ) :
 		zeros( pad ) + str;
-	if ( negative ) {
-		str = '-' + str;
-	}
-	return str;
+	return prefix + str;
 }
 
 

lib/node_modules/@stdlib/string/base/format-interpolate/test/test.format_integer.js

@@ -162,7 +162,7 @@ tape( 'the function returns an integer-formatted token argument (precision)', fu
 		'precision': 5,
 		'padRight': true
 	};
-	expected = '10000';
+	expected = '00010';
 	actual = formatInteger( token );
 	t.strictEqual( actual, expected, 'returns expected value' );
 

lib/node_modules/@stdlib/string/base/format-interpolate/test/test.js

@@ -529,6 +529,83 @@ tape( 'the function returns a formatted string (`d` specifier, minimum width, ze
 	t.end();
 });
 
+tape( 'the function returns a formatted string (`d` specifier, minimum width, zero-padded, sign)', function test( t ) {
+	var expected;
+	var tokens;
+	var actual;
+
+	tokens = formatTokenize( '%+05d' );
+	actual = formatInterpolate( tokens, 42 );
+	expected = '+0042';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	tokens = formatTokenize( '% 05d' );
+	actual = formatInterpolate( tokens, 42 );
+	expected = ' 0042';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	tokens = formatTokenize( '%+05d' );
+	actual = formatInterpolate( tokens, -42 );
+	expected = '-0042';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	t.end();
+});
+
+tape( 'the function returns a formatted string (`d` specifier, precision, left-justified)', function test( t ) {
+	var expected;
+	var tokens;
+	var actual;
+
+	tokens = formatTokenize( '%-8.3d|' );
+	actual = formatInterpolate( tokens, -7 );
+	expected = '-007    |';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	tokens = formatTokenize( '%-+6.2d|' );
+	actual = formatInterpolate( tokens, 5 );
+	expected = '+05   |';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	t.end();
+});
+
+tape( 'the function returns a formatted string (`x` and `X` specifiers, alternate form, minimum width, zero-padded)', function test( t ) {
+	var expected;
+	var tokens;
+	var actual;
+
+	tokens = formatTokenize( '%#08x' );
+	actual = formatInterpolate( tokens, 255 );
+	expected = '0x0000ff';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	tokens = formatTokenize( '%#08X' );
+	actual = formatInterpolate( tokens, 255 );
+	expected = '0X0000FF';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	t.end();
+});
+
+tape( 'the function returns a formatted string (`f` specifier, minimum width, zero-padded, sign)', function test( t ) {
+	var expected;
+	var tokens;
+	var actual;
+
+	tokens = formatTokenize( '%+08.3f' );
+	actual = formatInterpolate( tokens, 3.14159 );
+	expected = '+003.142';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	tokens = formatTokenize( '% 08.3f' );
+	actual = formatInterpolate( tokens, 3.14159 );
+	expected = ' 003.142';
+	t.strictEqual( actual, expected, 'returns expected output' );
+
+	t.end();
+});
+
 tape( 'the function returns a formatted string (`f` specifier)', function test( t ) {
 	var expected;
 	var tokens;

lib/node_modules/@stdlib/string/base/format-interpolate/test/test.zero_pad.js

@@ -67,3 +67,36 @@ tape( 'the function pads an argument with zeros to a minimum width on the right'
 
 	t.end();
 });
+
+tape( 'the function inserts zeros after a sign and a hexadecimal prefix', function test( t ) {
+	var expected;
+	var actual;
+	var str;
+
+	str = '+42';
+	expected = '+0042';
+	actual = zeroPad( str, 5 );
+	t.strictEqual( actual, expected, 'pads' );
+
+	str = ' 42';
+	expected = ' 0042';
+	actual = zeroPad( str, 5 );
+	t.strictEqual( actual, expected, 'pads' );
+
+	str = '0xff';
+	expected = '0x0000ff';
+	actual = zeroPad( str, 8 );
+	t.strictEqual( actual, expected, 'pads' );
+
+	str = '0XFF';
+	expected = '0X0000FF';
+	actual = zeroPad( str, 8 );
+	t.strictEqual( actual, expected, 'pads' );
+
+	str = '+3.142';
+	expected = '+003.142';
+	actual = zeroPad( str, 8 );
+	t.strictEqual( actual, expected, 'pads' );
+
+	t.end();
+});